Aromatic Ethers Research Articles

Enantioselective aminomethylation of 1-(benzyloxy)propan-2-one with an aromatic C-ethyl substituted propargyl amine ether

Enantioselective aminomethylation of 1-(benzyloxy)propan-2-one with an aromatic propargyl amino ether in the presence of a chiral pseudoephedrine catalyst in an aqueous medium gave anti / syn products with high yields and optical purity.

High-energy-density flexible graphene-based supercapacitors enabled by atypical hydroquinone dimethyl ether

Supercapacitor is an electrochemical energy-storage technology that can meet the green and sustainable energy needs of the future. However, a low energy density was a bottleneck that limited its practical application. To overcome this, we developed a heterojunction system composed of two-dimensional (2D) graphene and hydroquinone dimethyl ether- an atypical redox-active aromatic ether. This heterojunction displayed a large specific capacitance (Cs) of 523 F g−1 at 1.0 A g−1, as well as good rate capability and cycling stability. When assembled in symmetric and asymmetric two-electrode configuration, respectively, supercapacitors can work in voltage windows of 0 ∼ 1.0 V and 0 ∼ 1.6 V, accordingly, and exhibited attractive capacitive characteristics. The best device can deliver an energy density of 32.4 Wh Kg−1 and a power density of 8000 W Kg−1, and suffered a small capacitance degradation. Additionally, the device showed low self-discharge and leakage current behaviors during long time. This strategy may inspire exploration of aromatic ether electrochemistry and pave a way to develop electrical double-layer capacitance (EDLC)/pseudocapacitance heterojunctions to boost the critical energy density.

Synthesis, Biological Evaluation, in silico ADMET and Molecular Docking of new 1,4‐Dihydropyridine Derivatives Bearing Ether Substitution as Calcium Channel Blockers

AbstractA set of 1,4‐dihydropyridine derivatives were synthesized, possessing methyl or ethyl esters at positions 3 and 5, an aliphatic or aromatic ether group at position 2, and a thienyl ring at position 4. The calcium channel blocking activity of these derivatives was investigated using K+‐induced contraction on the longitudinal smooth muscles of guinea pig ileum (GPILSM). Our findings showed that the derivatives had IC50 ranging from 0.5 to 5.2 μM. Among the synthesized compounds, compound including methoxy group in position 2 and ethyl acetate in positions 3 and 5, with IC50=0.55±0.58 μM was almost comparable to that of nifedipine (IC50=0.27±1.23 μM). The results of docking studies and biological evaluation of synthetic compounds were consistent. According to the physicochemical and drug‐likeness parameters, it is predicted that the synthesized compounds can be a suitable candidate for calcium channel blocking.

Pharmacological Properties of <i>Genista sagittalis</i> L. (Fabaceae) Grown in Turkey

The genus Genista L. (Family: Fabaceae) is a plant having several traditional uses for treating common ailments such as diabetes, ulcer, and respiratory diseases. In this current study, the composition of essential oil and the biological activities of Genista sagittalis L. (Fabaceae) from Kocaeli: Yuvacık Dam Basin have been studied. A total of fourteen components were identified in the essential oil. The identified compounds belonged to straight-chain alkane, aromatic ether, and terpenoid derivatives. The antibacterial activity analyses demonstrated that G. sagittalis flower extract only had low activity against P. mirabilis and P. aeruginosa with MICs 1 to 2 mg/mL, as the peduncle extract showed strong anti-QS activity at 1.3 mg/mL. To the best of our knowledge, the current work is the first to report the antimicrobial and anti-quorum sensing activity of G. sagittalis growing in Turkey. Double-stranded DNA binding affinity investigations of the flower and peduncle ethanol extracts indicate that there are interactions with double-stranded DNA and related binding constants (Kb) were found as 1.97×103±0.37 and 3.68×102±0.44 for the flower and peduncle extract, respectively.

SYNTHESIS AND PROPERTIES OF AROMATIC ETHERS OF PETROLEUM AND CARBOXYLIC ACIDS

Chloralhydrate of the acids, which is separated from the sea oils, have been synthesized and its physical-chemical properties have been researched accordingly. After this, it was possible to receive a series of aromatic ethers in a result of the interaction of the separated chloralhydrate with phenol, benzyl alcohol, α-naphthol and additionally an optimal condition for the current process has been determined as well. It has been also determined that a reaction of acylation takes a place between the chloralhydrate of low-molecular petroleum acids and a series of aromatic alcohols at approximately 70-800C temperature and the aromatic ethers of natural petroleum acids have been obtained in a result of this stated reaction. As regards the structure of these obtained aromatic ethers, it has been confirmed by IR-spectroscopy and investigated in terms of its physical-chemical properties as well. Keywords: petroleum acids, acid chloride, thionyl chloride, phenol, benzyl alcohol, α-naphthol.

Enhancing photocatalytic C-O/N coupling reaction over covalent organic frameworks by pull-push electron group regulation

Covalent organic frameworks (COFs) have emerged as novel materials in photocatalytic technology for green energy and chemicals production. However, exploring highly efficient and stable COFs based materials for photocatalytic aromatic ethers and amines synthesis is still urgent. Herein, olefin-linked COFs modified with or without –F/-OCH3 groups were constructed by Knoevenagel condensation reaction. In addition, Ni active sites were embedded in the frameworks through bipyridine units to afford highly efficient and repeatable photocatalytic C-O/N coupling reaction. Through this strategy, it was found that the -F group modification greatly elevated photogenerated carriers separation efficiency attributing to its strong electronegativity and electron-withdrawing properties. Photocatalytic experiments conveyed that sp2c-F-COFdpy-Ni displayed highest photocatalytic activity and catalyzed cross-coupling of aryl C-O/N both with high yield exceeding 99 %, and exhibited excellent substrate compatibility for aryl bromides substituted with electron-withdrawing/donating groups. This investigation provides new insights into structure design of COFs for photocatalytic organic transformation.

Microwave-assisted catalytic transfer hydrogenolysis of lignin-derived aromatic ethers over Ru/C

Cleavage of aromatic ether bonds through hydrogenolysis is one of the most promising routes for depolymerisation and transformation of lignin into value-added chemicals. Herein, we investigate the catalytic transfer hydrogenolysis (CTH) of benzyl phenyl ether (BPE), as a model molecule of α-O-4 lignin linkages, over commercial Ru/C under microwave irradiation using 2-propanol as H-donor. By tuning the reaction parameters, such as time, temperature and catalyst amount, BPE was fully converted, at 150 °C in 5 min of irradiation, with a related aromatics selectivity of 92%. Phenylethylphenyl ether (PPE), and diphenyl ether (DPE), as a models of β-O-4 and 4-O-5 linkages, respectively, were also considered to this scope and under optimized reaction conditions, >99% and 72% conversion, respectively, were achieved with >89% aromatics selectivity. Remarkably, catalytic tests with moderate conversions clearly showed that the cleavage of etheric C-O bond was the primary step under CTH conditions, while the hydrogenations of the aromatic rings take place in a subsequent step. Overall, the screening of the reaction parameters was crucial to avoid the hydrogenation of aromatic rings. No less significant was the Ru/C stability, which has been recycled at least six times without any noticeable activity loss.

Synthesis of cardanol grafted hydrophilic polymers and its mechanism of coal dust inhibition

A novel hygroscopic sodium cardanol polyoxyethylene ether sulfate (SCPES) dust suppressant was synthesized via graft copolymerization, sulfonation, and alkalization reactions of cardanol and polyoxyethylene. The critical micelle concentration, chemical synthesis and wetting mechanism of SCPES were investigated using pyrene fluorescence spectroscopy, Fourier transform infrared spectroscopy, quantum chemistry and molecular dynamics software. SCPES was synthesized in three steps: first, the phenolic –OH of cardanol was de-H and grafted with polyoxyethylene to form cardanol polyoxyethylene ether (CPE); second, the H atom of CPE was replaced by the –SO3H of H2SO4 to generate cardanol polyoxyethylene ether sulfate (CPES); finally, the H+ of CPES was alkalized with the OH− of NaOH to form SCPES. It was found that the active centers of the three reactions were all at the O–H bond, the activation energies were 233.66, 85.99, and − 66.91 KJ/mol, and the final composite had distinct aromatic ether (Ar–O, R–O), S–O, and S = O infrared absorption peaks, proving that SCPES had been successfully prepared. 0.10 g/L and 0.25 g/L were the critical association concentration and critical micelle concentration of SCPES, and the surface tension and contact angle at the critical micelle concentration were 33.12 mN/m and 39.5°. Compared with the H2O-lignite system, the H2O-SCPES-lignite system exhibited an increase in the total number of hydrogen bonds from 2082 to 2136, a decrease in the interaction energies from − 13863.35 kcal/mol to − 17817.77 kcal/mol, and an increase in the diffusion coefficients of H2O molecules from 0.12 to 0.73. The results indicated that the long hydrophobic tail chain in the molecular structure of SCPES was entangled with the hydrophobic sites on the coal surface, acting as intermediate carriers between water and coal to improve the wettability of coal dust, and providing a new technical means for coal dust inhibition.

Oxovanadium(V)‐Catalyzed Deoxygenative Coupling Reaction of Alcohols with Trimethylsilyl Enol Ethers in the Presence of MS3A

AbstractOxovanadium(V)‐catalyzed deoxygenative coupling reaction of allyl alcohols with trimethylsilyl enol ethers was demonstrated to afford γ,δ‐unsaturated carbonyl compounds in one‐step. The catalytic deoxygenative coupling reaction of allyl alcohols proceeded smoothly with both aromatic and aliphatic trimethylsilyl enol ethers. This catalytic deoxygenative coupling system could be applied to the deoxygenative coupling reaction of benzyl alcohols with trimethylsilyl enol ethers, providing the corresponding carbonyl compounds. Furthermore, a gram‐scale catalytic synthesis of the γ,δ‐unsaturated carbonyl compound was successfully performed to validate the scalability of this catalytic deoxygenative coupling reaction.

Separation and Analysis of Oxygen-Containing Compounds in a Shaanxi Middle/Low-Temperature Coal Tar.

A middle/low-temperature coal tar (M/LTCT) was obtained from a low-temperature carbonization plant in Shaanxi, China. The M/LTCT was separated into light components and coal tar pitch through extraction. A series of alkanes, aromatic hydrocarbons, oxygen-containing arenes (OCAs), and nitrogen-containing arenes were fractionated from light components by medium-pressure preparative chromatography with gradient elution using petroleum ether and ethyl acetate. They were analyzed using a gas chromatography-mass spectrometer (GC-MS) and a Fourier transform infrared spectrometer. The OCAs were analyzed by a Fourier transform Orbitrap MS (quadrupole exactive Orbitrap mass spectrometer), and the molecular distribution of the O 1-O 6 species was studied. OCAs are mainly oxygen-containing aromatic compounds, including aromatic phenols, furans, alkoxy aromatic hydrocarbons, aromatic ethers, aromatic aldehydes, aromatic ketones, and aromatic acids. The position of the oxygen atom on the aromatic ring and the condensation form of the aromatic ring are studied.

Experimental study on optimizing reaction path for promoting the gasification of coal in supercritical water

Coal gasification in supercritical water (SCW) has great potential in industrial application for converting coal into hydrogen-rich gas in a clean and efficient manner. However, when the reaction conditions are improperly coupled with reaction path, undesirable side reactions would take place, which is prone to reduce the efficiency of converting coal into hydrogen-rich gas. It is revealed that the condensation of aromatic structures and the formation of aromatic ether (Car-O) groups are the restrained reactions according to the reaction path obtained by studying the variation of gas–liquid-solid products during supercritical water gasification (SCWG) of coal. Methanol, Fe2O3 and Ni(CH3COO)2·4H2O are added to inhibit the restrained reactions. It is found that these all facilitate the cracking and gasification of aromatic structures. Fe2O3 and Ni(CH3COO)2·4H2O except methanol, reduce the formation of Car-O groups effectively. The optimal concentration of these corresponding to the greatest promotion is 7.5 wt% (methanol), 2.5 wt% (Fe2O3) and 2.5 wt% (Ni(CH3COO)2·4H2O), respectively. Ni(CH3COO)2·4H2O (2.5 wt%) has the highest promotion on the production of H2 and CO, as well as the cracking and gasification of aromatic structures. The corresponding maximum yields of H2 and CO increase by 0.29 and 1.85 times, respectively. Fe2O3 (2.5 wt%) has the greatest promotion on the decomposition of Car-O groups, and the relative content of Car-O groups decreases by 80.86%. This research provides the theoretical basis for regulating the ordered conversion of coal into hydrogen-rich gas during SCWG of coal.

Enhanced demethylation of aromatic ether to phenol over NiAl hydrotalcite-derived nickel sulfide catalyst

The production of phenol from lignin or its model compounds, instead of cumene oxidation is very interesting from the viewpoint of sustainability and economics. The selective demethylation of anisole was an efficient but challenging route to produce phenol. In this work, we demonstrated the fabrication of nickel sulfide (Ni9S8+NixS6) nanoparticles on Al2O3 matrix by a facile in situ sulfidation of NiAl hydrotalcite and announced that nickel sulfide can serve as efficient active site for the demethylation of anisole for the first time. The as-designed 4Ni1Al-S catalyst exhibited a hierarchical morphology with a high particle density and high dispersion, affording a 95.6% yield of phenol in the demethylation of anisole under relative milder reaction temperature (270 °C) when compared to the reported state-of-the-art results. By comprehensive characterizations and experiments, we inferred that the nickel sulfide exsolved from the LDH structure exhibited stronger metal-support interaction than that obtained from the impregnation method, which not only benefits the uniform dispersion of active nickel sulfide but also results in the electronic transfer from Ni center to Al2O3 support. As a consequence, enhanced demethylation activity was achieved on 4Ni1Al-S in comparison to Ni-S/Al2O3-IM.

Functional zirconium phosphate nanosheets enabled transfer hydrogenolysis of aromatic ether bonds over a low usage of Ru nanocatalysts

Catalytic hydrogenolysis of aromatic ether bonds is a highly promising strategy for upgrading lignin into small-molecule chemicals, which relies on developing innovative heterogeneous catalysts with high activity. Herein, we designed porous zirconium phosphate nanosheet-supported Ru nanocatalysts (Ru/ZrPsheet) as the heterogeneous catalyst by a process combining ball milling and molten-salt (KNO3). Very interestingly, the fabricated Ru/ZrPsheet showed good catalytic performance on the transfer hydrogenolysis of various types of aromatic ether bonds contained in lignin, i.e., 4-O-5, α-O-4, β-O-4, and aryl-O-CH3, over a low Ru usage (<0.5 mol%) without using any acidic/basic additive. Detailed investigations indicated that the properties of Ru and the support were indispensable. The excellent activity of Ru/ZrPsheet originated from the strong acidity and basicity of ZrPsheet and the higher electron density of metallic Ru0 as well as the nanosheet structure of ZrPsheet.

Tailoring the Electronic Ru-Al2O3 Interaction to Regulate Reaction Barriers for Selective Hydrogenolysis of Aromatic Ether

Aromatics are desirable products from the depolymerization/valorization of lignin; however, it is still challenging to achieve selective hydrogenolysis of the C–O bond with the preservation of aromatic rings. In this work, the electronic Ru-Al2O3 interaction was tailored by controlling the sizes of supported Ru nanoparticles to regulate the profiles of energy barriers for selective hydrogenolysis of diphenyl ether (DPE, modeling compound of lignin). Complementary characterizations and kinetic studies demonstrate that a stronger electronic metal–support interaction (EMSI) occurs between smaller Ru nanoparticles and Al2O3, leading to a more electron-deficient Ru domain. This tailored electronic structure dramatically increases the barrier of an undesired secondary reaction (i.e., ring hydrogenation), outstripping that of DPE hydrogenolysis for the production of aromatics. In addition, although the latter barrier also increases over smaller and more electron-deficient Ru, the much more abundant active site compensates for the increased barrier and enhanced the apparent reactivity. The catalyst bearing the smallest Ru particle displays the highest activity and selectivity under the tested conditions. This work provides an approach to control selectivity in hydrotreatment by regulating the energy barriers along the reaction pathway.

Ion Exchange Properties of Crosslinked and Carboxylated Peanut (Arachis Hypogaea L.) Testa Extract

After polymerization via polycondensation of catechin units in the acetone extract of peanut (arachis hypogaea L.) testa (PTE) using phosphorus oxychloride (POCl3) as a crosslinking agent, POCl3-crosslinked PTE (Crosslinked-PPTE) was functionalized by etherification (PC-PTE) using monochloroacetic acid (MCAA) in the presence of an alkali according to the method of Williamson ether synthesis. Subsequent to characterization by Fourier Transform Infrared spectroscopy (FTIR) as well as physical properties, Crosslinked-PPTE was assessed for cation exchange capacity (CEC) and pH at point of zero charge (ZPHC) following demonstrated capacity to remove heavy metal ions in single and multi-elements aqueous solutions by Atomic Absorption Spectrometry (AAS) technique while functionalized (carboxymethylated) Crosslinked-PPTE (PC-PTE) was further characterized by degree of substitution (DS). FTIR absorption bands due to -C-O-P=O, -P=O, P-O-C- and R-O-P-OH stretching vibrations were seen at 1350/1250, 1244/1246, 997/993 cm-1 respectively. Asymmetric and symmetric stretching vibrations of the -C=O of a COOH, Ar-O-C- of an aromatic ether as well as -P-O-C - of an aromatic PO43-, R-P=O of a -PO43-, -R-O-P- and R-O-P-OH of a PO43- ester created by crosslinked and carboxymethylated PTE respectively were seen at 1743, 1377, 1278, 1190, 1062 and 823 cm-1. The results obtained showed that 0.6 was the DS of PC-PTE while 6.72 meq/g and 3.57 defined the CEC and pH (zpc) respectively of Crosslinked-PPTE. Quantitative removal of Fe2+, Ni2+, Pb2+, Cu2+ and Zn2+ in laboratory simulated metal ion wastewater (LSW) to the levels of 84.4, 81.7, 76.5, 72.0 and 75.1% respectively was achieved using Crosslinked-PPTE resin in batch adsorption experiments in which the efficiency was found to depend significantly on the temperature and pH of the water as well as initial adsorbate concentration and contact time but partially on the amount of adsorbent used was observed to be independent of the speed of stirring of the wastewater. Stable, Matakana and fine powder crosslinked-PPTE which is insoluble in water and common laboratory solvents holds great potential in the purification of heavy metal ions polluted water

Generation and characterization of bio-oil obtained from the slow pyrolysis of cooked food waste at various temperatures

Bio-oil was generated from slow pyrolysis of cooked food waste (CFW) at various temperatures (300–500 °C). Then NMR analysis was used as a qualitative means to characterize the bio-oil for its nature (aliphatic or aromatic), and then the compounds were confirmed and quantified using the GC–MS. This analysis indicated that the pyrolysis at low temperature (300 °C) mainly generated carbonyl compounds (Aldehydes, Ketones, Esters, and Oxo groups), Levoglucosans, and Furans (17%, 24%, and 38%, respectively) considered as typical pyrolysis chemicals. Similarly, the pyrolysis at medium temperature (400 °C) generated other compounds that were present in significant quantity, including sugars, aliphatic compounds, nitrogen compounds, acids, phenolic compounds, and alcohols. However, their fraction decreased with an increase in pyrolysis temperature to 500 °C and the fraction of aromatics increased significantly (>60%). This aromatics fraction was much more than that in a bio-oil from typical biomass which can be attributed to distinctively different chemical characteristics of CFW due to presence of additional compounds such as starch, proteins, waxes and oils in CFW. Moreover, the composition of aromatic fraction was better because a very high percentage of aromatic ethers (>58%) e.g. Benzene, 1,3-bis (3-phenoxyphenoxy), was found at 500 °C which can be converted into aliphatic alkanes, aliphatic alcohols, aromatic derivatives and platform chemicals by means of catalyst addition.

Reactive phosphaphenanthrene aromatic ether diamine endowing epoxy resin with excellent fire resistance, liquid oxygen compatibility and cryogenic mechanical properties

Endowing conventional epoxy resin (EP) with great liquid oxygen compatibility (LOC) and desirable ultra-low-temperature mechanical property is essential to the applications in fields of cryogenic engineering. A reactive phosphaphenanthrene aromatic ether diamine (PBAH) flame retardant including phosphorus and nitrogen elements was synthesized by a simple one-pot reaction between HB (salicylaldehyde), DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) and BAPP (2,2-bis[4-(4-aminophenoxy)phenyl]propane), then utilized to modify EP/BCI (biscitraconimide resin) system as a multifunctional component in this study. The resultant EP represented improved heat stability; outstanding fire resistance with an improvement of limiting oxygen index (LOI) value of 31.7% and V-0 rating in UL-94 test, as well as the desirable LOC and enhanced mechanical properties. The tensile strength (130.49 MPa) and fracture toughness (2.93 MPa·m1/2) increased by 51.3% and 78.7%, respectively, and the bending strength (255.30 MPa) increased by 116.8% than that of pure EP at cryogenic (77 K). All these results demonstrated the reactive PBAH showed a broaden potential in ultra-low-temperature engineering fields.

Extraction of Metal Ions Using a Calix[4]arene Carboxylic Acid Derivative in Aromatic Ethers

If calixarenes can be dissolved in a relatively safe non-halogen solvent, they can be used in a liquid-liquid extraction process suitable for mass processing. In the present study, extraction behavior of metal ions using a calix[4]arene carboxylic acid derivative (tOct[4]CH2COOH) dissolved in aromatic ethers was investigated. The solubility of tOct[4]CH2COOH in aromatic ethers decreases with increase of the length of aliphatic side chain of the ethers. The solubility of tOct[4]CH2COOH in 1-butoxybenzene (BB) was 28.0 mmol/L, which is smaller than that in chloroform but is higher than those in hexane and toluene. Divalent metal ions Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Pb(II) were extracted using tOct[4]CH2COOH in BB through proton exchange reaction at similar pH range in toluene, which is higher than that in chloroform. The extraction reaction of Cu(II) using tOct[4]CH2COOH in BB was determined by slope analysis and loading test. The stoichiometry between tOct[4]CH2COOH and Cu(II) was 2:1.

Использование элементоорганических соединений некоторых элементов III, V групп и пероксидов в синтезе органических соединений и полимеров. Памяти профессора В.А. Додонова

Professor Viktor Alekseevich Dodonov (11.07.1933 – 27.09.2021) was the Head of the Department of Organic Chemistry of the Chemical Faculty of Lobachevsky State University of Nizhny Novgorod from 1971 to 2016. He was an Honored Scientist of the Russian Federation, full member of the Academy of Engineering Sciences of the Russian Federation, Fulbright Professor, the author of 42 patents, 500 scientific articles, the Head of the Scientific and Pedagogical school “Organic and organoelement chemistry: radical reactions in the liquid phase”. He synthesized new classes of organic and organoelement peroxides based on non-transition elements. He created unique adhesives based on an amine complex with an organoboronic compound, capable of gluing polymers with low surface energy at room temperature (polyethylene, polypropylene, polyvinyl chloride, and especially Teflon). He showed the possibility of oxidation of hydrocarbons and their derivatives (alkanes, alkenes, alkyl-substituted aromatic hydrocarbons, alcohols, ketones, ethers and esters, and sulfides) at room temperature with tert-butylhydroperoxide in the presence of the aluminum and bismuth compounds. He found that under certain conditions the air oxygen became the main participant in the reaction, while peroxide and metal act as catalysts. He used phenyl derivatives of antimony and bismuth under metal complex catalysis by copper and palladium compounds for selective O-, N-, C-phenylation of organic substances including OH, NH, C=C-H groups under mild conditions at 20–50 °C. He studied the processes of gas-phase decomposition of organometallic compounds of chromium and nickel in order to obtain metal-containing (metallic, carbide, oxide) films and coatings.

Targeted development of sustainable green catalysts for regioselective acylation of aromatic ethers with carboxylic acidsviachlorosulfonic acid coated on poly(guanidine–triazine–sulfonamide) grafted quartz–γ-Fe2O3

Friedel–Crafts (FC) acylation of aromatic compounds is considered one of the essential and valuable reactions in organic synthesis.